Devices are known for separating labels, caps and other objects from containers made of plastics, as disclosed in documents JP2011005848, KR20000019385 and WO2011/012113.
It is known that for recycling plastics, in particular for recycling post-consumer containers or bottles made of PET, such containers or bottles are first subjected to a pre-washing step to eliminate foreign matter that has stuck to the container, and, in a subsequent step, are processed inside a rotating drum apparatus to remove labels or other bodies. Subsequently, the bottles and containers move to a subsequent grinding step in which they are reduced into flakes of small dimensions, for example of the order of a centimeter. The flakes are lastly subjected to further washing steps in order to remove contaminants and/or solid particles that have remained sticking to the flakes of plastics.
Often, the containers and bottles leaving the rotating drum apparatus and directed towards the grinding step are accompanied by fragments or labels or even entire labels or other bodies that the aforesaid apparatus was unable to separate and move totally away from the containers. Consequently, in the subsequent grinding and washing steps in addition to the containers and bottles also the aforesaid bodies and labels and other contaminating materials are found that, if they are not completely removed, can influence or even compromise the recycling material obtained. Naturally, the presence of residual contaminants beyond a certain limit leads to recovered plastics being obtained that have a degree of purity that is not industrially satisfactory. On the other hand, the need to use a large amount of washing water and chemical additives with the relative treatment costs, disposal problems and great energy consumption for heating the water are limits and weak points for which it would be desirable to intervene to obtain a general improvement in the process. There is thus still a need to seek a solution that enables labels, caps and other bodies to be separated more effectively from the bottles and containers and at the same time enable the cost and use of energy, water and additives to be reduced for washing plastics in flakes, or at least, for the same cost and amount of use of the latter, enables a purity of the recovered plastic material to be obtained that is much greater than that which is obtainable with the prior-art processes and systems that are currently in use.